Tag: M.W=150-200

Christoffers, Jens; Rossler, Ulrich published the artcile< One-pot generation and conversion of trichloroacetimidates for the racemization-free allylation and benzylation of α-hydroxyesters and the enantiopure synthesis of a chiral diglycole>, Recommanded Product: (S)-Dimethyl 2-hydroxysuccinate, the main research area is trichloroacetamidate generation benzylation allylation hydroxy ester; diglycole chiral preparation.

O-Allylations and O-benzylations of the α-hydroxy esters (S)-Et lactate and mandelate and di-Me maleate are performed without racemization. The reagents applied, O-allyl- and O-benzyltrichloroacetimidates ROC(CCl3):NH (R = PhCH2, allyl), are prepared and converted in a one-pot procedure. After protection by benzylation, (S)-(-)-Et lactate is converted by a sequence of carbonyl reduction, alc. activation, ether formation, and deprotection to the optically active diglycole (S,S)-(+)-Bis(2-hydroxypropyl) ether.

Journal fuer Praktische Chemie (Weinheim, Germany) published new progress about Allylation. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Recommanded Product: (S)-Dimethyl 2-hydroxysuccinate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zhou, Xin-Yue; Zhang, Ming; Liu, Zhong; He, Jia-Hao; Wang, Xiao-Chen published the artcile< C3-Selective Trifluoromethylthiolation and Difluoromethylthiolation of Pyridines and Pyridine Drugs via Dihydropyridine Intermediates>, SDS of cas: 33402-75-4, the main research area is trifluoromethylthiopyridine preparation one pot regioselective; pyridine trifluoromethylthiolation difluoromethylthiolation hydroboration oxidative aromatization; difluoromethylthiopyridine preparation regioselective one pot.

Herein, authors report a method for unprecedented C3-selective C-H tri- and difluoromethylthiolation of pyridines. The method relies on borane-catalyzed pyridine hydroboration for generation of nucleophilic dihydropyridines; these intermediates react with trifluoromethylthio and difluoromethylthio electrophiles to form functionalized dihydropyridines, which then undergo oxidative aromatization. The method can be used for late-stage functionalization of pyridine drugs for the generation of new drug candidates.

Journal of the American Chemical Society published new progress about Aromatization. 33402-75-4 belongs to class esters-buliding-blocks, and the molecular formula is C8H9NO2, SDS of cas: 33402-75-4.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Dalidovich, Tatsiana; Nallaparaju, Jagadeesh Varma; Shalima, Tatsiana; Aav, Riina; Kananovich, Dzmitry G. published the artcile< Mechanochemical Nucleophilic Substitution of Alcohols via Isouronium Intermediates>, Recommanded Product: (S)-Dimethyl 2-hydroxysuccinate, the main research area is alc amine mechanochem nucleophilic substitution; tertiary amine preparation; Alcohols; amines; isouronium; mechanochemistry; nucleophilic substitution.

Herein a new mechanochem. method was developed for nucleophilic substitution of alcs. using fluoro-N,N,N’,N’-tetramethylformamidinium hexafluorophosphate (TFFH) and K2HPO4 as an alc.-activating reagent and a base, resp. Alc. activation and reaction with a nucleophile were performed in one milling jar via reactive isouronium intermediates. Nucleophilic substitution with amines afforded alkylated amines in 31-91% yields. The complete stereoinversion occurred for the SN2 reaction of (R)- and (S)-Et lactates. Substitution with halide anions (F-, Br-, I-) and oxygen-centered (CH3OH, PhO-) nucleophiles was also tested. Application of the method to the synthesis of active pharmaceutical ingredients has been demonstrated.

ChemSusChem published new progress about Alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Recommanded Product: (S)-Dimethyl 2-hydroxysuccinate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Jones, Matthew A.; Morton, James D.; Coxon, James M.; McNabb, Stephen B.; Lee, Hannah Y.-Y.; Aitken, Steven G.; Mehrtens, Janna M.; Robertson, Lucinda J. G.; Neffe, Axel T.; Miyamoto, Shigeru; Bickerstaffe, Roy; Gately, Karl; Wood, Jacqueline M.; Abell, Andrew D. published the artcile< Synthesis, biological evaluation and molecular modeling of N-heterocyclic dipeptide aldehydes as selective calpain inhibitors>, Name: Ethyl 5-formyl-1H-pyrrole-2-carboxylate, the main research area is peptide aldehyde preparation inhibitor calpain eye lens opacification; cDNA sequence Ovis calpain 1 2 catalytic subunit.

Ten N-heterocyclic dipeptide aldehydes (4-13) have been synthesized and evaluated as inhibitors of ovine calpain 1 (o-CAPN1) and ovine calpain 2 (o-CAPN2). N-(5-formylpyrrole-2-carbonyl)-L-valylleucinal (9; IC50 values of 290 and 25 nM against o-CAPN1 and o-CAPN2, resp.) was the most potent and selective o-CAPN2 inhibitor, displaying >11-fold selectivity. The amino acid sequences of o-CAPN1 and o-CAPN2 have been determined Because of the lack of available structural information on the ovine calpains, in silico homol. models of the active site cleft of o-CAPN1 and o-CAPN2 were developed based on human calpain 1 (h-CAPN1) X-ray crystal structure (PDB code 1ZCM). These models were used to rationalize the observed SAR for compounds 4-13 and the selectivity observed for 9. The o-CAPN2 selective inhibitor 9 (CAT0059) was assayed in an in vitro ovine lens culture system and shown to successfully protect the lens from calcium-induced opacification.

Bioorganic & Medicinal Chemistry published new progress about Aldehydes Role: PAC (Pharmacological Activity), SPN (Synthetic Preparation), BIOL (Biological Study), PREP (Preparation) (dipeptides). 7126-50-3 belongs to class esters-buliding-blocks, and the molecular formula is C8H9NO3, Name: Ethyl 5-formyl-1H-pyrrole-2-carboxylate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Maki, Toshikatsu; Ishihara, Kazuaki; Yamamoto, Hisashi published the artcile< N-Alkyl-4-boronopyridinium Halides versus Boric Acid as Catalysts for the Esterification of α-Hydroxycarboxylic Acids>, Product Details of C6H10O5, the main research area is boric boronic acid catalyst condensation hydroxycarboxylic acid alc; resin bound boronic acid catalyst condensation hydroxycarboxylic acid alc; alpha beta hydroxy ester chemoselective preparation; hydroxybenzoate ester chemoselective preparation; amide preparation; chemoselective condensation alpha beta hydroxy carboxylic hydroxybenzoic acid alc; boronic boric acid catalyst chemoselective condensation hydroxyacid alc; alkyl boronopyridinium halide boric acid catalyst condensation hydroxyacid alc.

α- And β-hydroxycarboxylic and ortho-hydroxybenzoic acids undergo condensation reactions with alcs. in the presence of either boronic acids such as 4-borono-1-methylpyridinium iodide (I) or in the presence of boric acid to yield α-hydroxy or ortho-benzoate esters chemoselectively. When excess alcs. are used to prepare the hydroxyesters, I is the more effective catalyst of those tested, while for esterifications using less than three equivalent of the alc. boric acid is a more effective catalyst. Resin-bound 1-benzyl-4-boronopyridinium chloride is recycled nine times as a catalyst for the dehydrative esterification of mandelic acid in isobutanol to give iso-Bu mandelate in 95-99% conversion. Esterification of α-hydroxy acids with alcs. in the presence of boric acid is preferred to esterification of carboxylic acids; for example, esterification of 2-methyl-2-hydroxypropanoic acid and benzoic acid with one equivalent of 1-octanol in the presence of boric acid yields octyl 2-hydroxy-2-methylpropanoate in 90% and octyl benzoate in 1% yield. I also acts as a catalyst for the condensation of amines and carboxylic acids to give amides; condensation of 5-amino-1-pentanol and benzenebutanoic acid in anisole in the presence of I yields Ph(CH2)3CONH(CH2)5OH (II) in 82% yield; condensation of II with 2-hydroxy-2-methylpropanoic acid in toluene in the presence of boric acid provides Ph(CH2)3CONH(CH2)5OCOC(OH)Me2 in 91% yield.

Organic Letters published new progress about Alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Product Details of C6H10O5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Cortes-Clerget, Margery; Lee, Nicholas R.; Lipshutz, Bruce H. published the artcile< Synthetic chemistry in water: Applications to peptide synthesis and nitro group reductions>, Safety of H-Leu-OEt.HCl, the main research area is peptide synthesis coupling water green chem solvent cosolvent; amine synthesis nitro group reduction carbonyl iron powder safety.

Amide bond formation and aromatic/heteroaromatic nitro-group reductions represent two of the most commonly used transformations in organic synthesis. Unfortunately, such processes can be especially wasteful and hence environmentally harmful, and may present safety hazards as well, given the reaction conditions involved. The two protocols herein describe alternative technologies that offer solutions to these issues. Polypeptides can now be made in water at ambient temperatures using small amounts of the designer surfactant TPGS-750-M, thereby eliminating the use of organic solvents as the reaction medium. Likewise, a safe, inexpensive and efficient procedure is outlined for nitro-group reductions, using industrial iron in the form of carbonyl iron powder (CIP), an inexpensive item of commerce. The peptide synthesis will typically take, overall, 3-4 h for a simple coupling and 8 h for a two-step deprotection/coupling process. The workup usually consists of a simple extraction and acidic/basic aqueous washings. The nitro reduction procedure will typically take 6-8 h to complete, including setup, reaction time and workup.

Nature Protocols published new progress about Amide group (amide bond). 2743-40-0 belongs to class esters-buliding-blocks, and the molecular formula is C8H18ClNO2, Safety of H-Leu-OEt.HCl.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Grob, C. A.; Weissbach, O. published the artcile< The preparation of oxindole derivatives from o-chloronitrobenzenes and cyanoacetic and malonic acid esters>, Category: esters-buliding-blocks, the main research area is .

Chlorobenzenes activated by a single o-NO2 group underwent smooth nucleophilic substitution by the K derivatives of NCCH2CO2Et (I) and CH2(CO2Et)2 (II) in Me3COH as solvent. The resulting 2-nitrophenylmalonic ester derivs, were readily converted into o-O2NC6H4CH2CO2H (III) and derivatives of oxindole and indole resp. I (49.0 g.) and then 31.5 g. o-O2NC6H4Cl (IV) in 75 cc. hot absolute Me3COH added with stirring to 16.3 g. K in 370 cc. absolute Me3COH, refluxed 10 hrs. with stirring, cooled, acidified with dilute HCl, and concentrated in vacuo at 30-40°, the residue dissolved in Et2O and extracted with dilute aqueous Na2CO3, and the aqueous extract acidified and extracted with Et2O gave 33.0 g. o-O2NC6H4CH(CN)CO2Et (V), prisms, m. 59-60° (MeOH and sublimed at 50°÷0.1 mm.) (all m.ps. are corrected), b0.09 139-41°; the forerun from the distillation of the V deposited 3-6% anthroxanic acid nitrile (VI), needles, m. 58-9° (Me2CO and sublimed at 50°÷11 mm.). VI refluxed 12 hrs. with 1:1 AcOH-20% HCl gave nearly 100% anthroxanic acid (VII), needles, m. 187-95° (decomposition) with the formation of a decomposition product, m. above 230°. VI heated with MeOH-HCl gave the Me ester of VII, needles, m. 67-8° (aqueous Me2CO). V (9.4 g.) in 80 cc. N Na2CO3 kept 10 days at 22° deposited 5.8 g. o-O2NC6H4CH2CN (VIII), leaflets, m. 82-4°. IV (10.5 g.) treated in the usual manner with I and the aqueous Na2CO3 phase from the processing kept 14 days at 25° gave 8.1 g. VIII, light yellow lancets, m. 82-3° (aqueous MeOH). V (5.0 g.) refluxed 15 hrs. with 50 cc. 2:1 AcOH-20% HCl and evaporated in vacuo, the residue partitioned between Et2O and H2O, the Et2O layer extracted with 2N KHCO3, and the extract acidified and extracted with Et2O yielded 3.4 g. III, light yellow needles, m. 139-41° (aqueous Me2CO). V (1 g.) in 15 cc. AcOH heated 45 min. with occasional shaking on the steam bath with 0.75 g. Fe powder and evaporated, the residue dissolved in Et2O, and the product isolated with 2N KHCO3 yielded 0.6 g. 2-amino-3-carbethoxyindole, leaflets, m. 180-1° (sublimed at 150°÷0.2 mm.) (C6H6-petr. ether). II (61.5 g.) and then 30 g. IV in 50 cc. Me3COH refluxed 26 hrs. with 15 g. K in 350 cc. absolute Me3COH under N, acidified with dilute H2SO4, concentrated in vacuo at about 40°, and extracted with Et2O, the residual crude o-O2NC6H4CH(CO2Et)2 (IX) distilled twice at 0.3 mm. yielded 19 g. Et ester of VII, needles, m. 66-7° (MeOH), and a smaller amount of Et ester of III, needles, m. 64-5° (MeOH). Crude IX from a similar run refluxed 15 hrs. with 125 cc. AcOH and 125 cc. 20% HCl and worked up in the usual manner gave 18 g. III. II (82 g.) and then 47 g. 2,3-Cl2C6H3NO2 in 40 cc. hot absolute Me3COH added to 19.9 g. K in 430 cc. Me3COH, refluxed 20 hrs. with stirring, and evaporated in vacuo, and the residue acidified with dilute HCl and extracted with Et2O gave 112 g. 2,6-Cl(O2N)C6H3CH(CO2Et)2 (X). The crude X refluxed 24 hrs. with 600 cc. AcOH and 400 cc. 20% HCl and evaporated in vacuo, the residue partitioned between Et2O and 2N KHCO3, and the aqueous phase acidified and extracted with Et2O yielded 44.3 g. 2,6-Cl(O2N)C6H3CH2CO2H, m. 190-2° (aqueous Me2CO).

Helvetica Chimica Acta published new progress about 30095-98-8. 30095-98-8 belongs to class esters-buliding-blocks, and the molecular formula is C9H9NO4, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Paterson, Ian; Findlay, Alison D.; Noti, Christian published the artcile< Total synthesis of (-)-spirangien A, an antimitotic polyketide isolated from the myxobacterium Sorangium cellulosum>, SDS of cas: 617-55-0, the main research area is spirangien A preparation polyketide antimitotic antitumor agent asym synthesis.

An expedient first total synthesis of (-)-spirangien A, a potent cytotoxic and antifungal polyketide of myxobacterial origin, is described. A method for the synthesis of the title compound is reported here. By using a common 1,3-diol intermediate obtained by an efficient aldol-reduction sequence for installation of the C15-C18 and C25-C28 stereotetrads and a reagent-controlled boron aldol coupling followed by spiroacetalization, a highly convergent strategy was developed for construction of the elaborate spiroacetal core. Conversion of this advanced spiroacetal intermediate into (+)-spirangien diene, obtained previously by controlled degradation of spirangien A, was then achieved by installation of the truncated side-chain using an allylboration-Peterson sequence. The total synthesis of (-)-spirangien A was then achieved by the controlled attachment of the unsaturated C1-C12 side-chain, avoiding exposure to light. A Stork-Wittig olefination and double Stille cross-coupling sequence was exploited to install a delicate conjugated pentaene chromophore featuring alternating (Z)- and (E)-olefins, leading initially to the Me ester of spirangien A, which proved significantly more stable than the corresponding free acid. Subsequent careful hydrolysis afforded (-)-spirangien A. validating the relative and absolute configuration.

Chemistry – An Asian Journal published new progress about Absolute configuration. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, SDS of cas: 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Reddy, B. V. Subba; Babu, R. Anji; Ramana Reddy, M.; Reddy, B. Jagan Mohan; Sridhar, B. published the artcile< Intramolecular C-O/C-S bond insertion of α-diazoesters for the synthesis of 2-aryl-4H-benzo[d][1,3]oxazine and 2-aryl-4H-benzo[d][1,3]thiazine derivatives>, Electric Literature of 30095-98-8, the main research area is arylbenzoxazine carboxylate preparation; arylbenzothiazine carboxylate preparation; arylamidophenyl diazoacetate copper triflate catalyst intramol cyclization; arylthioamidophenyl diazoacetate copper triflate catalyst intramol cyclization.

An intramol. C-O insertion of 2-(2-arylamidophenyl)-2-diazoacetate was achieved using a catalytic amount of copper triflate under mild conditions to produce 2-aryl-4H-benzo[d][1,3]oxazine-4-carboxylate in good yields. In addition, 2-diazo-2-(2-arylthioamidophenyl)acetate afforded the corresponding 2-aryl-4H-benzo[d][1,3]thiazine derivatives under similar conditions. This was the first example of the synthesis of benzoxazines and benzothiazines from ortho-amidophenyl diazoacetate and ortho-thioamidophenyl diazoacetate, resp.

RSC Advances published new progress about Aromatic amides Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 30095-98-8 belongs to class esters-buliding-blocks, and the molecular formula is C9H9NO4, Electric Literature of 30095-98-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Xing, Xiu; Liu, Yan; Shi, Ming-Liang; Li, Kun; Fan, Xin-Yue; Wu, Zhong-Liu; Wang, Na; Yu, Xiao-Qi published the artcile< Preparation of chiral aryl alcohols: a controllable enzymatic strategy via light-driven NAD(P)H regeneration>, Recommanded Product: Ethyl 3-oxo-3-phenylpropanoate, the main research area is rhodamine B labeled UiO 67 immobilized enzyme catalyst preparation; alc preparation enantioselective; ketone reduction photochem enzyme catalyst.

Controllable and mild photoenzymic production of chiral alcs. RCH(OH)R1 [R = Ph, 4-pyridyl, 2-naphthyl, etc.; R1 = H, Me, CH2CO2Me, etc.] was realized by coupling a versatile photochem. NAD(P)H regeneration system with (R)- or (S)-selective ketoreductases. The efficiency of NAD(P)H regeneration was improved using a rhodium functionalized metal organic framework, namely Rh-UiO-67, to adjust and control electron transport and electron utilization. Furthermore, six different ketoreductases could be successfully immobilized on Rh-UiO-67 and combined with the light-driven NAD(P)H regeneration system to produce chiral aryl alcs. Various chiral alcs. with complementary (R)- and (S)-conformations could be constructed by this method with high yields (97%) and excellent stereoselectivity (>99% ee).

New Journal of Chemistry published new progress about Alcohols, chiral Role: SPN (Synthetic Preparation), PREP (Preparation). 94-02-0 belongs to class esters-buliding-blocks, and the molecular formula is C11H12O3, Recommanded Product: Ethyl 3-oxo-3-phenylpropanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics